Commit 17291a1f by Jay Belanger

### (Radix modes): Mention twos-complement notation.

parent 14467b99
 2009-11-16 Jay Belanger * calc.texi (Radix modes): Mention twos-complement notation. 2009-11-16 Juanma Barranquero * makefile.w32-in (INFO_TARGETS, DVI_TARGETS, clean): Add semantic. ... ...
 ... ... @@ -13173,6 +13173,42 @@ are displayed with at least enough digits to represent in the current radix. (Larger integers will still be displayed in their entirety.) With the command @kbd{C-u d 2}, Calc will display integers using twos-complement notation, using the current word-size to determine the number of bits. When using twos-complement notation, a negative word size might be appropriate (@pxref{Binary Functions}). If the absolute value of the word size is @expr{w}, then twos-complement notation will represent the integers in the symmetric interval from @texline @math{-2^{w-1}} @infoline @expr{-2^(w-1)} to @texline @math{2^{w-1}-1} @infoline @expr{2^(w-1)-1} using the binary numbers from @expr{0} to @expr{2^w}; the integers from @expr{0} to @texline @math{2^{w-1}-1} @infoline @expr{2^(w-1)-1} will be represented by their usual binary form and the integers from @texline @math{-2^{w-1}} @infoline @expr{-2^(w-1)} to @expr{-1} will be represented by first adding @expr{2^w} to them and then using the usual binary form (so they will be represented by the integers from @texline @math{2^{w-1}} @infoline @expr{2^(w-1)} to @expr{2^w}). Calc will represent a twos-complement integer by the radix @expr{2}, two @kbd{#} symbols, and the @expr{w} binary digits (including any necessary leading zeros). Numbers that are not displayed in twos-complement notation (i.e., that aren't integers from @texline @math{-2^{w-1}} @infoline @expr{-2^(w-1)} to @c ( @texline @math{2^{w-1}-1}) @infoline @expr{2^(w-1)-1}) will be represented using Calc's usual binary notation. @node Grouping Digits, Float Formats, Radix Modes, Display Modes @subsection Grouping Digits ... ... @@ -17969,7 +18005,7 @@ of the binary operations described here operate modulo @expr{2^w}. In particular, negative arguments are converted to positive integers modulo @expr{2^w} by all binary functions. If the word size is negative, binary operations produce 2's complement If the word size is negative, binary operations produce twos-complement integers from @texline @math{-2^{-w-1}} @infoline @expr{-(2^(-w-1))}
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment